To 2D outline treatment, besides adjust rate of cutting tool feed, adjusting on cutting angle and cutting force, cutting tool method amends a method to had become a kind of means that provides attraction quite, and very reliable. Want to make what feed rate carries in whole treatment process constant, although be in,do not have high-powered machine tool servo implement adjust feed cutting angle and cutting force, also can come true through method of amendatory of cutting tool method. In 2D treatment, simple to I-shaped 2 dimension outline uses general and equidistant algorithm directly outside (inside) slant radius of a cutting tool gets place protruding stage (groove) treatment knife course, treatment gives the outline appearance of protruding stage and groove. But, because this is planted,the cutting tool way that treatment method place makes is not the workpiece contour line that expects any more, do not apply to model of antrum wall by in outward treatment. Stori and Wright put forward above all forward cutting tool method revises a method. This task puts forward algorithmic to this correction algorithm, so that it can apply at the cutter track of aleatoric geometry, the test and verify in experimenting this is algorithmic. Stori and Wright algorithm 1 tradition is forward cutting tool method amends algorithm to maintain a constant cutting feed, include the stable cutting course of geometrical body to protruding, stori and Wright put forward a famous method to amend cutting tool way. This method produces constant correction cutter track in 2D outline treatment. Give an initiative flat curve, this curve expressed to be about to want the curved surface outline of treatment. By a series of dot P (I) ∈ R2 (I=1, ... , np) express. This algorithmic main purpose is to produce 1 to slant newly outline of buy treatment curved surface and positions of a series of cutting tool center, so that a constant feed can maintain inside whole handling time. Graph 1 it is the cutting tool way that Stori and Wright offer of correction algorithm simplify sketch map. Assume in give a dot to go up foregone and following variable: P (I) , p (I+1) -- of the photograph node of current cutting tool and workpiece curved surface and back-to-back move issue a photograph node; Q (I) ∈ R2 (I=1, ... , NQ) -- the photograph of the workpiece curved surface that cutting tool and newest treatment cross is nodical. The cutting point of view that gives R of cutting tool radius and place need can adjust α *en gets. Slant newly Q of buy music noodle (I+1) ∈ R2 (I=1, ... , NQ) with O of has amended position of cutting tool center (I+1) ∈ R2 (I=1, ... , NO) , specific algorithm is as follows. (1) through following equation computation slants newly buy curved surface nods Q (I+1) . Q (I+1) =Q (I) + λ T (I) ① so that ② of T (i) P (i + 1) = L of λ of Q(i) + among them, l is the waist grows for R and the end that two waists included angle is *e N of cutting angle α is long, namely L =2r2? ? En of α of 1 Cos, and T (I) ∈ R2, it is to slant newly the unit of buy curved surface cuts vector, if pursue,1 is shown. (2) slant newly through be in with computation of lower part Cheng the unit of buy curved surface cuts vector. ③ of φ of Cos of φ of Sin of φ of Sin of φ of T (i + 1) =P (i + 1) Q(i + 1) P (i + 1) Q(i + 1) Cos among them, φ is the banking angle that the unit cuts vector; T (I) it is vector P (I+1) - Q (I+1) (3) pass O of position of center of cutting tool of computation of the following equation (I+1) . ④ of π of 2 Cos (4) set I=i+1, and repeat ④ of measure ① ~ , go complete till cutting tool a treatment method. Notable is, by above the position of cutting tool center that algorithm creates can apply at only by P (I) the curved surface of protruding bag geometry that defines. Should applying at be not protruding geometry curved surface is unworkable. Be in actual in, especially in mould treatment, the protruding that often complex aggregate and barely are satisfied includes a requirement, so this algorithm must be passed in improving ability to be able to apply at effective treatment. 2 forward the 2D outline that this task group offers according to Stori and Wright place machines cutter track correction algorithm algorithmic, put forward a kind of new method a future life to become a kind constant the cutting tool way that feed leads, so that this kind of algorithm can apply at including gibbous the geometrical cutter track of the aleatoric type with concavity. Basic algorithm is shown 2 times like the graph. What give out unlike Stori and Wright is algorithmic, those who put forward is forward the result that cutter track correction algorithm cannot assure to convergence is optimized at on maths. However, an advantage with this the biggest algorithm is it can use rough sketch of aleatoric 2D geometry, the algorithm of unlike Stori and Wright, be confined to protruding geometry. To constant of cutting feed backward correction algorithm of cutting tool method is current, this task group put forward a kind of new method a future life to become a kind again constant the cutting tool way that feed leads, so that this kind of algorithm can apply at including gibbous the geometrical cutter track of the aleatoric type with concavity. The geometrical outline that with 1 initiative flat curve expresses to need to machine a spare parts, and provide a primitive outline slant buy curve, this curve is the method of finish machining cutting tool of need, can extract from inside NC code. This algorithmic main purpose is calculated namely before 1 of method of opposite finish machining whole cutting tool way, call its semifinishing machining method. Method of half-and-half finish machining undertakes correction, make cutting tool OK in final finish machining method undertake machining with constant rate, and acquire constant cutting amount. What this research pays close attention to is the 2D outline treatment that by straight handle crop Duan Xi knife has, and consider the interference between cutting tool and workpiece only. What mention here " cutting tool method is amended " can do following understanding, namely to given final finish machining method, will undertake machining through revising the cutting point of view that makes what cutting tool needs with place constant, and this algorithmic goal that the task advances is cutter track of half-and-half finish machining undertake correction, amend cutting tool namely circumferential with Pk of semifinishing machining curved surface (I) nodical position, get a new positional P*k thereby (I) . Make with this kind of method cutting feed angle from α *e (N I) adjust the α *e of a need (N I) . Pk of semifinishing machining method (I) amend can pass pair of Ok-1 (I) amend accomplish. O*k-1 of new semifinishing machining method (I) can pass slant simply buy P*k (I) give out. O*k-1 (I) detailed algorithm can have consideration according to following measure. (1) it is suppose in finish machining, the contrail of cutting tool center is Q (I) ∈ R2 (I=1, ... , nk) . This contrail is slanted according to place of cutting tool radius by the outline of treatment spare parts namely a curve of buy, if pursue,3 are shown. En of feed angle α (I) ∈ R2 (I=1, ... , NQ) can by Ok of position of cutting tool center (I) , the music surface contact of cutting tool and new treatment nods Qk (I) ∈ R2 (I=1, ... , nk) , the dot Pk on cutting tool and semifinishing machining curved surface (I) ∈ R2 (I=1, ... , nk) , these 3 nod a composition. Pk of semifinishing machining curved surface (I) generate first at finish machining, its machine method to be Qk-1 (I) ∈ R2 (I=1, ... , nk-1) . (2) given to be in finish machining Qk-1 of position of cutting tool center (I) ∈ R2 (I=1, ... , nk-1) , can Qk (I) to workpiece treatment area slants buy R of radius of a cutting tool, calculate thereby a cutting tool is circumferential the node of the spare parts curved surface with new treatment. This operation can express to be: QK (I) = Offset (Qk (I) , + R) (I=1, ... , nk) ⑤ among them, function Offset (Q (I) , x) expressed to pass Q of parallel and cranky contrail (I) the contrail that the distance of a X generates. Nextpage (3) the nodical P*k that computation gives a need (I) , namely the photograph all round semifinishing machining face and cutting tool is nodical. This computation is to make En of feed angle α (I) the *en of α of finish machining angle of contented need (I) , search P*k namely (I) , make ∠ P*k (I) · Ok (I) · Ok (I) = α *en (I) , and ｜ ｜ P*k (I) - Ok (I) | | =r (I=1, ... , nk) . Among them, "∠ " the point of view that expressed to be formed by the dot. P*k (I) defined has amended semifinishing machining way, if pursue,3 are shown. (4) make I=i+1, and repeat measure ③ and ④ , till I=Nk. (5) through slanting buy radius machines P*k of area area contrail (I) R of radius of a cutting tool, computation gives the contrail of center of correction cutting tool of semifinishing machining: O*k-1 (I) ∈ R2 (I=1, ... , nk-1) . Such O*k-1 (I) = Offset (P*k (I) , - R) (I=1, ... , nk-1) . (6) to given cutting tool and workpiece, the *en of feed angle α that gave place need when computation (I) hind, can make cutting tool keeps a constant cutting force from beginning to end in finish machining phase. 1 emulation experiment passes example of application of amendatory of method of retrorse cutting tool particular trial comes test and verify is backward the effectiveness of correction algorithm of cutting tool method. This experiment will be in respect of handling time of sum of errors of cutting force, gather and traditional method undertake contrast. In this experiment, *en of needs cutting angle α can get through the following measure. Assume give cutting tool radius to be R, radial cutting deepness is the method of S, the En of cutting angle α of phase of cutting of so online sex can be calculated come out; Apply α En in this algorithm next (I) will calculate the *en of α of feed cutting angle of a need. Actually that is to say, using this algorithm is for the cutting angle in whole treatment phase cannot the level that deviate machines level in linear. If the graph is shown 4 times, use a simple curved horn geometry to serve as example. Among them, s is radial cutting deepness, α En is feed cutting angle, r is cutting tool radius. Graph 5 in the way of correction semifinishing machining that showed this algorithmic computation earnings exceeds, traditional semifinishing machining method and finish machining method. In finish machining phase, undertook contrast to traditional semifinishing machining and the cutting point of view that adopt this algorithm to undertake amendatory semifinishing machining. From the graph 6 in can see apparently, the cutting angle of traditional method from 11. 5 ° jump to 19 ° abruptly, what can cause treatment so is not stable, make treatment face quality not high thereby; And this algorithm can make however the level of feed angle change that cutting tool maintains to had been compared in phase of whole finish machining. Because the join of linear and circular arc is nodded,a little discontinuous change in the curve is, because the computational error in emulate is caused,this is. 2 particular trials come on specific treatment test and verify this algorithmic effectiveness. This experiment uses a high speed 3 coordinate machining center, model is ProLIGHT 1000Machining Center, if the graph is shown 4 times,add the rough sketch of workpiece. If the treatment condition that is used at this experiment expresses 1 to show. To compare cutting performance, used 3 kinds of methods. (1) treatment is politic 1. The outline that machines a method to use a convention originally slants buy machines a method, and apply in semifinishing machining and finish machining, what carry feed rate in machining a process is constant. (2) treatment is politic 2. Be those who apply at semifinishing machining is constant the correction method of feed method, namely backward cutting tool method revises a method, and finish machining method and strategy 1 use same method, and machine maintain from beginning to end in the process constant feed rate. Nextpage (3) treatment is politic 3. This strategy uses feed rate to adjust treatment method, alterable feed is used to lead treatment way in finish machining method, so that make in process of whole finish machining,cutting force maintains 1 constant value. Way of semifinishing machining way and finish machining method and treatment are politic 1 identical. Constant feed rate is kept in semifinishing machining. Need to notice here, the value that alterable feed leads is by cutting force forecast model place to decide. In the strategy of 3 kinds of trials of above, experiment material all is quench steel JISSKD61; Cutting tool diameter is D=10mm, 4 blade. 3 tests result and in discussing to experiment in treatment, FXY of force of cutting of the complex on XY plane can be measured through dynamometer. Graph 7 in the cutting force in demonstrating method of 3 kinds of finish machining. Machining strategy 1 in, force of the cutting when cutting tool enters circular arc phase adds unexpectedly; Machining strategy 2 in, the change that can see cutting strength through using this algorithm is in by limitation 17N less than; Machining strategy 3 in the change that can see cutting strength is reduced, but the change of its cutting force is more than strategy 2. Because lack high-powered servo to control a system to answer the change that feed leads,this basically is, cannot adjust the cutting force of a need. Graph 8 the geometrical error picture that give is measured through coordinate measuring instrument in showing in curved surface outline is machined, geometrical error can pass the distance between effective treatment outline and good treatment outline to reach. Graph the error contrast that 9 clear ground compared strategy of 3 kinds of treatment to machine B from A pursues. Through the graph 8 and 9 can see, strategy is machined in the tradition 1 in, the error is the biggest when happening in cutting tool to enter circular arc, right now the error is achieved 14.
7 μ M, pass application however this algorithm, the biggest error when entering circular arc will be reduced greatly, achieve 4.
7 μ M, the smallest error will is less than 1.
0 μ M, the effect is very good. Treatment is politic 3 also solved machining error problem well, but the problem with the mainest method of this kind of treatment depends on a machine tool whether having high-powered servo, servo controls systematic function to machine immediate impact efficiency. In enter circular arc and when giving circular arc, machining error is the biggest, this is caused. It is especially in high speed treatment, when the machine tool lacks high-powered servo to control a system, this kind of phenomenon particularly apparent. This task offerred conclusion the law of unripe set prescription of a kind of new cutting tool way, its purpose is in finish machining level makes what cutting tool needs with place constant feed angle undertakes machining. Through using this method, can maintain in the cutting force of finish machining phase in a constant level, machine quality with respect to what improved curved surface naturally so. Experiment test and verify the dominant position that this algorithm is improving treatment efficiency and precision aspect. (1) slant at traditional outline relatively buy is algorithmic, amend algorithm originally through application, can make the change of force of the biggest cutting reduces 75%~83% . (2) when the machine tool that lacks high-powered servo, use this algorithm, below the case that does not drop treatment quality, get very good treatment quality, and the method that need not lead through adjusting cutting feed will machine. It is so in actual treatment application, it is apparently good that this algorithmic effect wants the leads through adjusting feed treatment method at the tradition. In 2D outline treatment, the treatment precision to the machine tool that improvement lacks high-powered servo in CNC Machining and efficiency have this task the port with reach its principal. CNC Milling
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